diff --git a/doc/contextual_checks.md b/doc/contextual_checks.md
index d0ff76b..244c649 100644
--- a/doc/contextual_checks.md
+++ b/doc/contextual_checks.md
@@ -27,38 +27,38 @@
 * No method with *override* keyword in a base class ✔
 * Override methods have the *override* keyword ✔
 * Override methods match the overriden method signature ✔
-* If method returns something, all code paths lead to an assign to *result* before return or block ends
-* No static override
+* If method returns something, all code paths lead to an assign to *result* before return or block ends ✔
+* No static override ✔
 
 ## Constructor
 
 * No reserved keyword in params ✔
 * Constructor name and class name are equal ✔
 * Constructor parameters and class parameters are equal ✔
-* Constructor calls the right super constructor if class is derived
-* Constructor does not call any super constructor if class is base
+* Constructor calls the right super constructor if class is derived ✔
+* Constructor does not call any super constructor if class is base ✔
 
 ## Instructions
 
 * Perform expression checks for Expr, Ite, Return and Assign
 * --
 * No reserved keyword declared in Block instructions ✔
-* Can only Assign to idents, attributes or static attributes
-* Cannot assign to *this* or *super*
+* Can only Assign to idents, attributes or static attributes ✔
+* Cannot assign to *this* or *super* ✔
 * Assign lhs exists ✔
 * Assign rhs is compatible with lhs ✔
-* Expression in an Ite instruction is of type Integer
+* Expression in an Ite instruction is of type Integer ✔
 
 ## Expressions
 
 * Call to new exists ✔
 * Called method exists ✔
 * Called method params are compatible with declaration ✔
-* Called static method exists in static class
-* Called static method params are compatible with declaration
+* Called static method exists in static class ✔
+* Called static method params are compatible with declaration ✔
 * Params in new call are compatible with ctor ✔
-* Numeric operators are used on Integer types
-* StrCat is used on Strings
+* Numeric operators are used on Integer types ✔
+* StrCat is used on Strings ✔
 * Identifiers are in scope ✔
 * Attributes exist ✔
-* Static Attributes exist
+* Static Attributes exist ✔
diff --git a/lib/contextual.ml b/lib/contextual.ml
index 66abac4..02bda84 100644
--- a/lib/contextual.ml
+++ b/lib/contextual.ml
@@ -183,7 +183,7 @@ let rec check_instr_block decls env (vars, li) =
 
 (** Performs the following checks:
     - Left-hand-side assign operand refers to either:
-      (a) An ident,
+      (a) An ident (not 'this' or 'super'),
       (b) (recusively) an attribute of a variable, or
       (c) A static attribute of a class.
     - Right-hand-side assign operand is compatible with the target variable
@@ -195,6 +195,7 @@ and check_instr_assign decls env (lhs, rhs) =
   let t1 = get_expr_type decls env lhs
   in let t2 = get_expr_type decls env rhs
   in let () = match lhs with
+      | Id "this" | Id "super" -> err (Printf.sprintf "cannot assign to 'this' or 'super'")
       | Id _ | Attr _ | StaticAttr _ -> ()
       | _ -> err (Printf.sprintf "cannot assign to an expression of type '%s'" t1)
   in let () =
diff --git a/progs/test.kat b/progs/test.kat
index 6872842..23f8995 100644
--- a/progs/test.kat
+++ b/progs/test.kat
@@ -1,7 +1,12 @@
-      {p1 : Integer
-      is 
-        {p2 : Integer
-        is 
-        p2 := 3;
- }
-      p1 := p2;}
\ No newline at end of file
+      class Base() is {
+        def Base() is {}
+      }
+      class Derived() extends Base is {
+        def Derived(): Base() is {}
+        def test() is {
+          b: Base
+          d: Derived
+          is b := new Base();
+        }
+      }
+      {}
diff --git a/test/context.ml b/test/context.ml
index 6c76109..dc174dc 100644
--- a/test/context.ml
+++ b/test/context.ml
@@ -228,9 +228,32 @@ let%test "override-methods-match-overriden-method-signature" =
   && expects_ctx_err (code "foo, bar : Integer, baz : Derived")
   && expects_ast (code "foo, bar : Integer, baz : Base")
 
-(* TODO: non-void-code-paths-lead-to-assign-to-result *)
-
-(* TODO: no-static-override *)
+let%test "non-void-code-paths-lead-to-assign-to-result" =
+  let template = Printf.sprintf {|
+      class Point1() is {
+        def Point1() is {}
+        def test(): Integer is { %s } /* in methods */
+        def static test2(): Integer is { %s } /* in static methods */
+      }
+      {}
+    |}
+  in let t1 = template "result := 0;"
+  in let t2 = (Fn.flip template) "result := 0;"
+  in let tests_err = [
+      {| if 10 then result := 10; else {} |};
+      {| if 10 then {} else result := 20; |};
+      {| foo: Integer is foo := 10; |};
+      {| return; result := 10; |};
+    ]
+  in let tests_ok = [
+          {| if 10 then result := 10; else result := 20; |};
+          {| foo: Integer is result := 10; |};
+          {| result:= 10; return; |};
+        ]
+  in tests_err |> List.map ~f:t1 |> List.for_all ~f:expects_ctx_err
+  && tests_err |> List.map ~f:t2 |> List.for_all ~f:expects_ctx_err
+  && tests_ok |> List.map ~f:t1 |> List.for_all ~f:expects_ast
+  && tests_ok |> List.map ~f:t2 |> List.for_all ~f:expects_ast
 
 (* ----------------------- Constructors -------------------------- *)
 
@@ -280,8 +303,15 @@ let%test "constructor-calls-right-super-constructor-if-class-derived" =
   && expects_ctx_err (code {| Base("hello", 10, "world") |})
   && expects_ast (code {| Base("hello", 10, 20) |})
 
-(* TODO: no-super-constructor-call-in-base-class *)
-
+let%test "no-super-constructor-call-in-base-class" =
+  let code = Printf.sprintf {|
+      class Point1() is {
+        def Point1() %s is {}
+      }
+      {}
+    |}
+  in expects_ctx_err (code " : Foo()")
+  && expects_ast (code "")
 
 (* ----------------------- Instructions -------------------------- *)
 
@@ -295,9 +325,57 @@ let%test "no-reserved-keyword-declared-in-block-instructions" =
   in List.for_all reserved ~f:(fun r -> expects_ctx_err (code r))
   && expects_ast (code "foo")
 
-(* TODO: only-assign-to-idents-or-attribs *)
-
-(* TODO: no-assign-to-this-or-super *)
+let%test "only-assign-to-idents-or-attribs" =
+  let code = Printf.sprintf {|
+      class Point1(var s1: String) is {
+        def Point1(var s1: String) is {}
+        var i1: Integer
+        var static i2: Integer
+        def foo(): Integer := 10
+      }
+      {
+        s: String
+        i, j: Integer
+        p: Point1
+        is %s := %s;
+      }
+    |}
+  in let ok = [
+      ("s", "\"hello\"");
+      ("i", "10");
+      ("Point1.i2", "10");
+      ("p.i1", "10");
+      ("p.s1", "\"hello\"");
+      ("new Point1(\"hello\").i1", "10");
+    ]
+  in let err = [
+      ("\"foo\"", "\"hello\"");
+      ("20", "10");
+      ("20", "10");
+      ("p.foo()", "10");
+    ]  
+  in err |> List.for_all ~f:(fun (a, b) -> expects_ctx_err (code a b))
+  && ok |> List.for_all ~f:(fun (a, b) -> expects_ast (code a b))
+
+let%test "no-assign-to-this-or-super" = 
+  let code = Printf.sprintf {|
+      class Base() is {
+        def Base() is {}
+      }
+      class Derived() extends Base is {
+        def Derived(): Base() is {}
+        def test() is {
+          b: Base
+          d: Derived
+          is %s := %s;
+        }
+      }
+      {}
+    |}
+  in expects_ctx_err (code "this" "new Derived()")
+  && expects_ctx_err (code "super" "new Base()")
+  && expects_ast (code "d" "new Derived()")
+  && expects_ast (code "b" "new Base()")
 
 let%test "no-undeclared-variable" =
   let code = Printf.sprintf {|
@@ -333,7 +411,14 @@ let%test "no-incompatible-assign-types" =
   && expects_ctx_err (code "p3" "p2")
   && expects_ast (code "p2" "p3")
 
-(* TODO: ite-expression-type-is-integer *)
+let%test "ite-expression-type-is-integer" =
+  let code = Printf.sprintf {|
+      {
+        if %s then {} else {}
+      }
+    |}
+  in expects_ctx_err (code "\"hello\"")
+  && expects_ast (code "10")
 
 (* ----------------------- Expressions -------------------------- *)
 
@@ -384,9 +469,39 @@ let%test "called-method-params-are-compatible-with-declaration" =
   && expects_ctx_err (code "10, 20, 30")
   && expects_ast (code "10, 20, \"hello\"")
 
-(* TODO: static-method-call-exists *)
+let%test "static-method-call-exists" =
+  let code = Printf.sprintf {|
+      class Point1() is {
+        def Point1() is {}
+        def static test1() is {}
+      }
+      {
+        Point1.%s();
+      }
+    |}
+  in expects_ctx_err (code "test2")
+  && expects_ast (code "test1")
 
-(* TODO: static-method-call-params-compatible *)
+let%test "static-method-call-params-compatible" =
+  let code = Printf.sprintf {|
+      class Point1() is {
+        def Point1() is {}
+        def static test1(i1, i2: Integer, b: Base, d: Derived) is {}
+      }
+      class Base() is {
+        def Base() is {}
+      }
+      class Derived() extends Base is {
+        def Derived(): Base() is {}
+      }
+      {
+        Point1.test1(%s);
+      }
+    |}
+  in expects_ctx_err (code "10, 20, new Base()")
+  && expects_ctx_err (code "10, 20, new Base(), new Base()")
+  && expects_ast (code "10, 20, new Base(), new Derived()")
+  && expects_ast (code "10, 20, new Derived(), new Derived()")
 
 let%test "params-in-new-call-compatible-with-constructor" =
   let code = Printf.sprintf {|
@@ -404,9 +519,15 @@ let%test "params-in-new-call-compatible-with-constructor" =
   && expects_ctx_err (code "10, 20, 30")
   && expects_ast (code "10, 20, \"hello\"")
 
-(* TODO: numeric-operators-used-on-integers *)
-
-(* TODO: string-operators-used-on-strings *)
+let%test "operators-used-on-right-type" =
+  let code = Printf.sprintf {|
+      { %s; }
+    |}
+  in let ops = [ "+"; "-"; "*"; "/"; "="; "<>"; "<"; ">"; ">="; "<=" ]
+  in ops |> List.for_all ~f:(fun op -> expects_ctx_err (code ("\"hello\" " ^ op ^ " 10")))
+  && expects_ctx_err (code "10 & \"hello\"")
+  && ops |> List.for_all ~f:(fun op -> expects_ast (code ("10" ^ op ^ "10")))
+  && expects_ast (code "\"hello\" & \"world\"")
 
 let%test "identifiers-are-in-scope" =
   let code = Printf.sprintf {|
@@ -440,7 +561,18 @@ let%test "attributes-exist" =
   in expects_ctx_err (code "foo")
   && expects_ast (code "attr")
   
-(* TODO: static-attributes-exist *)
+let%test "static-attributes-exist" =
+  let code = Printf.sprintf {|
+      class Point1() is {
+        def Point1() is {}
+        var static attr : Integer
+      }
+      {
+        Point1.%s := 5;
+      }
+    |}
+  in expects_ctx_err (code "foo")
+  && expects_ast (code "attr")
 
 (* ----------------------------------------------- *)
 
diff --git a/test/parse.ml b/test/parse.ml
index bb29eac..c3d3864 100644
--- a/test/parse.ml
+++ b/test/parse.ml
@@ -72,4 +72,19 @@ let%test "wrong-classbody" =
       { this.index := Point.incr(); this.hasClone := 0; }
     }
     {}
-  |} 
\ No newline at end of file
+  |} 
+
+let%test "no-static-override" =
+  let code = Printf.sprintf {|
+      class Derived() is {
+        def Derived() is {}
+        def static test() is {}
+      }
+      class Base() extends Derived is {
+        def Base(): Derived() is {}
+        def static %s test() is {}
+      }
+      {}
+    |}
+  in expects_parse_err (code "override")
+  && expects_ast (code "")